Devices that incorporate electric motors are used in a very wide range of applications. For applications that require sophisticated control of the electric motor, an electronic controller is often included in the device that is able to store parameters, implement complex control instructions, and monitor the status of the device. For example, an electronic controller can be used to control the speed and/or torque that is output by the motor according to a pre-defined profile that specifies the output torque as a function of the rotational position of the rotor.
An example of such an electronically controlled, motor-driven device is an electronically controlled, motor-driven valve actuator that is used, for example, to actuate a valve included in a process control system, or any other valve that requires sophisticated control of the valve actuation speed and/or the force or torque that is applied to the valve.
Often, although not always, devices with electronically controlled motors are in communication with a remote monitoring and control station that is able to receive status information from the electronic controller, and/or issue instructions to the controller. In other cases, the electronic controller itself may be situated remotely from the electric motor, which can create similar issues. It should be noted that, unless otherwise required by the context, disclosure presented herein with reference to remote “monitoring stations” are also applicable to remotely located electronic controllers.
Typically, if the electronic controller issues an urgent message, alert, or warning, it is received by the remote monitoring station and conveyed to users/operators of the device. If a plurality of similar devices is being simultaneously monitored and controlled by the remote station, then the alert issued by the control station may include identifying and/or location information that will allow the operator to determine which of the monitored devices requires attention.
Of course, the “monitoring station” may issue an alert to a mobile device such as a “smart phone” or laptop computer, or the monitoring station itself may be a mobile phone, laptop, or other computing device that is in wired or wireless communication with the electronic controller.
Unfortunately, when a large number of similar devices are being monitored, and/or when the monitored device is distant from the monitoring station and/or from the electronic controller, considerable time may be required before an operator receives an urgent alert and appropriate attention is given to the alerting device. It may be that no operator happens to be near the monitoring station when the alert is issued, or an appropriate mobile device may not be active at that moment. Once the alert is received, time may be required before the operator reaches the device that issued the alert. And if there is a plurality of similar devices in service at the same location, additional time may be required before the alerting device is identified.
Ironically, it is often the case that operating personnel are located in the vicinity of an alerting device, but may not become aware that attention is needed until someone near the monitoring station receives the alert and relays the information to personnel that are proximal to the alerting device. It can also happen that the alerting device includes a local monitoring display, but the local display is not within view of the nearby operators.
One approach is to include a perceptible alerting system as part of the electronically controlled, motor-driven device. For example, a flashing light, a local display, an acoustic speaker, or an audible siren can be co-located with the motor-driven device and activated by the electronic controller. In this manner, when an alert is issued, nearby personnel can become immediately aware that the device requires attention, and if there is a plurality of similar devices present, then the personnel can immediately identify which of the devices has issued the alert.
However, this approach is expensive, consumes additional space within or near the device, consumes additional power, and requires periodic testing and maintenance so as to ensure that the alerting system is functional. Furthermore, if the motor-driven device is located in a harsh environment, then this approach requires that the alerting system must be appropriately engineered and/or protected so that the environment does not degrade its function. If such alerts are relatively rare, as would be hoped, then the added expense of including such an alerting system can be prohibitive.
What is needed, therefore, is an apparatus and method of enabling an electronically controlled, motor-driven device to issue a local alert that will be perceptible to nearby operators, without adding to the cost, size, and/or power consumption of the motor-controlled device.